Although great progress has been made in the global fight against hunger in the past few decades, food insecurity is still an important hidden danger that plagues the healthy economic and social development of developing countries. Based on the argument of dependency theory and modernization theory, this paper analyzes the impact mechanism of agricultural FDI on food security in developing countries from the four perspectives of agricultural R D capacity, production level, import trade dependence and agricultural financial development, and then uses 60 countries in 1991- Cross-country panel data in 2013 were used to empirically test the impact and mechanism of agricultural FDI on food security by constructing a dynamic panel model. Studies have shown that agricultural FDI will have a significant negative effect on food security in developing countries, which means that the intent of international monopoly capital to taking advantage of another"s perilous state r than "helping others attain theirSaims . The heterogeneity test found that agricultural FDI has a greater negative effect on food security in developing countries with low levels of economic development, severe food shortages, geographic coastal locations, and non-UPOV member countries. Agricultural FDI is conducive to improving the level of food production in developing countries, but it has a significant negative effect on agricultural independent research and development capabilities and financial development, and it also increases developing countries’ agricultural import trade dependence. The conclusions of this article provide a factual basis for the argument of the impact of agricultural FDI between the dependency theory and the modernization theory.